30 And do not grieve the Holy Spirit of God, by whom you were sealed for the day of redemption.
for [unto] the day of redemption.
The “day of redemption” is the time when the believer will receive his new body in eternity. The Holy Spirit keeps the believer safe until he reaches glory itself, the completion of redemption in its entirety. The Holy Spirit is our guarantor for eternal life.
One day God will complete our redemption in its entirety.
The “day of redemption” is the next day on God’s prophetic calendar. It is the day when Jesus comes to take us to Himself permanently. At that time both our soul and body will be permanently transformed into the likeness of Jesus Himself.
Ro 8:23-24, Not only that, but we also who have the firstfruits of the Spirit, even we ourselves groan within ourselves, eagerly waiting for the adoption, the redemption of our body. 24 For we were saved in this hope, but hope that is seen is not hope; for why does one still hope for what he sees?
Eph 1:13-14, In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit of promise, 14 who is the guarantee of our inheritance until the redemption of the purchased possession, to the praise of His glory.